112251-39-5Relevant articles and documents
REACTION OF AROMATIC N-OXIDES WITH DIPOLAROPHILES. XII. STEREOSELECTIVE exo CYCLOADDITION OF 3,5-LUTIDINE N-OXIDE WITH N-SUBSTITUTED MALEIMIDES AND A FRONTIER MOLECULAR ORBITAL
Hisano, Takuzo,Harano, Kazunobu,Matsuoka, Toshikazu,Yamada, Hirotoshi,Kurihara, Masahiko
, p. 1049 - 1057 (2007/10/02)
Pericyclic reactions of 3,5-lutidine N-oxide with N-phenylmaleimides were investigated.The primary cycloadducts are thermally labile and undergo 1,5-sigmatropic rearrangement to give the 2,3-dihydropyridine derivartives.The proton nuclear magnetic resonance structural assignment of the 1,5-sigmatropy products implies that the primary cycloaddition proceeds through an exo transition state.The reaction behavior is discussed in terms of frontier molecular orbital theory, based on MINDO/3 and CNDO/2 calculations and kinetic data.It was concluded that the reaction falls into the category of a 'normal - type' cycloaddition and the exo cycloaddition is brough about by the unfavorable secondary orbital interaction.Keywords - 1,3-dipolar cycloaddition; 3,5-lutidine N-oxide; N-phenylmaleimide; kinetics; frontier molecular orbital; exo cycloaddition; 1,5-sigmatropy; substituent effect
